A TAAP - University of Arkansas at Monticello

Part Points
2 3 points possible
PART II Geometry Released Items––April 2007
1 point: Drawing of an equilateral triangle with correct and complete angle measures as
shown below.
Note: The “degree” label is required only for a score of 4.
AND
1 point: Correct and complete procedure shown and/or explained finding the measure
of the angle of the triangle whose vertex is the center point.
Work may contain a calculation or copy error.
Give credit for the following or equivalent:
• (All angles about the center point must add to 360º)
x = measure of angle of triangle whose vertex is the center point
30 + 30 + 30 + 30 + x + x + x + x = 360
120 + 4x = 360
4x = 240
x = 60, or
• 2(30) + 2x = 180
2x = 120
x = 60, or
• “The angles of the rhombus and the triangle whose vertex is the center point
make a 90º angle.” (Explanation of why this is true is required for a score of 4.)
“So the measure of the angle of the triangle is 90 – 30 = 60º.”
AND
1 point: Statement or drawing showing that the triangle is isosceles and the base angles
measure 60º (work may be missing).
Work may contain a calculation or copy error or may be based on an incorrect
measure of the “center angle” (work must be shown to receive credit).
Give credit for the following or equivalent:
• “Because the sides shared with the rhombi are congruent, the triangles are
isosceles. The base angles must be congruent and the sum of the angles in the
triangle must be 180°. I subtract 60 from 180 and get 120. Half of 120 is 60 for
each base angle,” or
• Diagram shows that 2 sides are of the triangle ≅ and the base angles measure
60º (with “center angle” measuring 60º), or
• “The triangle is isosceles. Since the 1 st angle is 60º, I know the base angles are
each 60º since 60 + 60 + 60 = 180, the triangle is equilateral.”
Note: Do not give credit if the response jumps to the conclusion that the
triangle is equilateral (or marks 3 sides ≅ on a diagram) without initially
stating or showing that 2 sides are ≅ .
Ex: “Measure of base angles = 60º since 180/3 = 60”
Ex: “It’s an equilateral triangle so all angles are 60 degrees.”
(Does not initially state that the triangle is isosceles.)
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